Cytotoxlc macrocyclic diterpenoid esters from Euphorbia cornigera

Root extract of Euphorbia cornigera Boiss. (Euphorbiaceae) was separated into seven (compound 1-7) isolates through multiple Craig's distributions and preparative HPLC. The structures and relative configuration of theses compounds were established via spectral analyses as 7,8,12-O-triacetyl-3-O-(2-methylbutanoyl)ingol (1), 3,8,12-O-triacetyl-7-O-(2-methylbutanoyl) = -ingol (2), 3,7,12-O-triacetyl-8-O-(2-methylbutanoyl)-ingol (3), 3,7,8-O-triacetyl-12-O-(2-methylbutanoyl)-ingo (4), 7,12-O-diacetyl-3-O-(2-methylbutanoyl)-8-O-methylingol (5), 3,12-O-diacetyl-7-O-(2-methylbutanoyl)-8-O-methylingol (6) and 3,7-O-diacetyl-12-O-(2-methylbutanoyl)-8-O-methylingol (7). All these compounds, except for 2, are novel metabolites and have not been reported earlier. It has further been demonstrated that all the compounds (1-7) are cytotoxic.